SNVS829F March   1999  – May 2026 LMP8480 , LMP8481

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
      1. 7.1.1 Theory of Operation
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
      1. 7.3.1  Basic Connections
      2. 7.3.2  Selection of the Sense Resistor
      3. 7.3.3  Using PCB Traces as Sense Resistors
      4. 7.3.4  VREFA and VREFB Pins (LMP8481 Only)
        1. 7.3.4.1 One-to-One (1:1) Reference Input
        2. 7.3.4.2 Setting Output to One-Half VCC or external VREF
      5. 7.3.5  Reference Input Voltage Limits (LMP8481 Only)
      6. 7.3.6  Low-Side Current Sensing
      7. 7.3.7  Input Series Resistance
      8. 7.3.8  Minimum Output Voltage
      9. 7.3.9  Swinging Output Below Ground
      10. 7.3.10 Maximum Output Voltage
    4. 7.4 Device Functional Modes
      1. 7.4.1 Unidirectional vs Bidirectional Operation
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Input Common-Mode and Differential Voltage Range
    2. 8.2 Typical Applications
      1. 8.2.1 Unidirectional Application With the LMP8480
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curve
      2. 8.2.2 Bidirectional Current Sensing Using the LMP8481
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 Application Curve
      3. 8.2.3 Typical Application With a Resistive Divider
  10. 9 Power Supply Recommendations
    1. 9.1 Power Supply Decoupling
  11. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information

7.3.5 Reference Input Voltage Limits (LMP8481 Only)

The maximum voltage on either reference input pin is limited to VCC or 12 V, whichever is less.

The average voltage on the two VREF pins, and thus the actual output reference voltage level, is limited to a maximum of 1.5 V below VCC, or 6 V, whichever is less. Beware that supply voltages of less than 7.5 V have a diminishing VREF maximum.

Both VREFA and VREFB can both be grounded to provide a ground referenced output (thus functionally duplicating the LMP8480).

Note that there can be a dynamic error in the VREF to output level matching of up to 100 µV/V. Normally this error is not an issue for fixed references, but if the reference voltage is dynamically adjusted during operation, this error must be taken into account during calibration routines. This error varies in both amplitude and polarity part-to-part, but the slope is generally linear.